In recent years, in the wireless communication standard for high-speed transmission such as WiGig (Wireless Gigabit) standard using millimeter-wave band signals, the degradation (error, for example) of the characteristic of a radio frequency circuit part has increasingly influenced on the communication performance.
Thus, when the radio frequency circuit part performs unbalance-to-balance transformation (balun) on an input signal from an antenna, since high accuracy is required as to error between differential output signals outputted by the unbalance-to-balance transformation (balun), a circuit system for reducing the error has become important.
Circuits for reducing the error between the differential output signals generated by the unbalance-to-balance transformation (balun) have been known (see Patent Literature 1, for example).